Arc device



March 30 1926. 1,578,973

J. FORCE ARC DEVICE Original Filed March 1, 1922 InJentor: Jonathan F0 P06 l'HS Attorney.

Patented Mar. 30, 1926.

UNITED STATES JONATHAN FORCE, OF LIVINGSTON, NEW JERSEY.

ABC DEVICE.

Original application filed Karen 1, 1922, Serial 17o. 540,276. Divided and this application filed October 5, 1823. Serial No. 666,831.

To all whom it may concern:

Be it known that I, JONATHAN Ponce, a citizen of the United States, residln at Livingston, county of Essex, State of ew Jersey, have invented certain new andnseful Improvements in Arc Devices (dlvision of m application Serial No. 54037 6, filed Marc 1,1922), of which the following 15 a specification.

The resent invention relates to devices in whic an arc is operated in a gaseous atmosphere between electrodes of which either the negative electrode alone, or both electrodes, operate at incandescence.

It is the object of my invention to 1mprove the o eration and life of an incandescent electro e device.

In are devices having electrodes operat' g at incandescence in an inert gas without consumption by oxidation, as in the case of open air arcs, an electrical effect 13 aptto cause the electrodes to waste away or disinte ate if the gaseous pressure is too high. On the other hand, too low a pressure causes accretion of the electrodes in such manner as to decrease the arcing distance between the electrodes. Either effect decreases the life of the devices.

As will be described hereinafter 111 detail, my improved arc device is provided with an auxlliary chamber connected by a suitable orifice with the main are chamber and being so proportioned and constructed that the gas pressure in the mam arc chamber is so regulated that the electrodes Wlll neither disintegrate nor build up by electrical action.

The accompanying drawing illustrates n Fig. 1 one embodiment of my invention in longitudinal section; and Figs. 2 and 3 illustrate a starting device applicable to this device.

The device shown in Fig. 1 1s particularly intended to operate as a lamp and therefore the electrodes 1, 2 are of substantially equal size, both electrodes consisting of a refracto metal preferably tungsten, and both or inarily being operated at bright incandescence. These e ectrodes are carried by conductors 3, 4, which may also consist of tungsten, and are sealed into the envelo e 5, which consists of glass having substantially the same coefiicient of expansion as tungsten. The tips 6, 7 of the conductors 3, 4 are bent at an angle to the rest of the conductors and toward each other so as to make the gap between the juxtaposed electrodes 1, 2 shorter than the distance between the conductors 3, 4. The envelope 5 contains a gaseous or gasifiable material which at the operating temperature of the lamp has a pressure high enough to enable an electrical discharge between the electrodes 1, 2 to assumo the characteristics of an electric arc, the energy of the discharge being enough to heat the electrodes to incandescence. For example, the bulb may contain a quantity 8 of mercury and a filling of an inert gas such as argon, or nitrogen. The wires 3, 4 are insulated from the mercury by insulating coatings 9, 10 of glass or the like.

he container or bulb 5 ordinarily is elongated to provide a condensing space above the arc. Preferably there is provided a separate chamber 11 which is smaller than the main chamber and connected to the main condensing chamber 13 by a constricted orifice 12 which is in line with the trajectory of the blast of mercury vapor emanating from the are between the electrodes 1, 2. The mercury vapor blast enters this auxiliary chamber 11, where the vapor pressure is determined by the temperature of the walls of the auxiliary chamber. This chamber therefore functions to regulate the gaseous pressure about the electrodes.

In order to prevent electrode disintegration during the operation of the arc, the parts of the device must be arranged and proportioned to enable the arc to operate with a voltage consumption below a limiting value, depending on the character of the device, particularly the length of the are. One of the conditions controlling the voltage drop between the electrodes is the pressure of the gas or vapor in which the arc operates. By the addition of the chamber 11, the pressure may be maintained at a lower value. Consequently the arc will be stabi lized at a lower voltage and the disintegration of the electrodes will be largely suppressed.

The auxiliary chamber should be proportioned to maintain the gas in the device at a pressure which is neither so high as to cause an increase of the arc gap by disintegration of the electrodes, nor so low as to cause accretion of metal u on the electrodes, and decrease of arc gap. 00 small a chamr increases the pressure and too large a chamber causes too much condensation and decreases the pressure. The constriction or throat should not be so small as to interfere with the return of condensed mercury nor so large as to admit so much mercury vapor that the chamber runs abnormally hot. In the case of an auxiliary chamber about one inch in diameter a throat of about inch diameter can be used.

At the end of the straight. portions of the conductors 3, a and adjacent the electrodes 1, 2 are located particles 14, loot a material having a higher electron emissivity than the lead wires. For example, these-beads may consist of tungsten containing thoria, or of metallic thorium, or an alloy of thorium. prefer to use tungsten containing about 5% thoria. This material may be prepared as described in Coolidge Patent 1,082,933. The thoriated tungsten mass maybe welded as a bead, or a short length of wire to the lead wires.

In the device illustrated in Fig. 1 both electrode leads are provided with thoriated tungsten for localizing the arc to permit operation with alternating current. W'hen an incandescent arc device is intended for operation with direct current, the cathode conductor onl need be provided with a material of big 1 electron emissivity.

\Vhen a device constructed in accordance with my invention is placed into operation, for example, by producing a high potential discharge between the electrodes 1, 2, the arc starts from the thoriated particles, 14, 15, remains there for a short time until the electrodes 1, 2 become heated, and then jumps to the electrodes where it continues to steadily operate.

When the are has once been started between the electrodes 1, 2 and therefore has heated these electrodes to incandescence, there is little or no tendency for the arc to desert the electrodes, but in the absence of the thoriated masses, the are would tend to flicker. The high electron emission from the lhoriated tungsten counteracts this ten dency and promotes a smooth, steady operation of the are. In my application Serial No. 540,276 claims are made on this feature of the described device.

Although the arc may be started by a high voltage discharge it is desirable in many cases to start the are by a low-voltage auxiliary discharge. In Figs. 2 and 3 I have illustrated devices embodying my invention having conductors 24, 25 connected to the electrode conductors 6, 7 and extending downwardly at such an angle that a circuit may be completed between these conductors 24, 25 by tilting the bulb, as shown in Fig. 2 by full lines. lVhen the lamp is tilted back slowly toward the position indicated by dotted lines, auxiliary arcs are formed at the terminals of the conductors 24, 25

with the mercury, thereby starting the main are between the electrodes 1, 2. A restoration of the bulb to an upright position causes these starting arcs to lengthen and break.

\Vhat I claim as new and desire to secure by Letters Patent of the United States, is

1. An electric discharge device compris ing a container, refractory are-sustaining electrodes therein operable at incandescence, a liquid in said container adapted to be actively vaporized during the operation of an are between said electrodes, and means for regulating the vapor pressure in said container to prevent substantial disintegration or accretion of metal on said electrodes during operation.

2. An electric discharge device comprising a main container, refractory arc-sustaining electrodes in said chamber, a vaporizable liquid therein, and a condensing chamber connected to said container by a constricted throat of such proportions that the flow of vapor therethrough is restricted while permitting the return of condensation liquid.

3. An electrical discharge device comprising an envelope consisting of a main chamber and a smaller auxiliary chamber connected with the main chamber by an orifice, electrodes in said main chamber of which the cathode consists of material adapted to emit electrons when heated, and a quantity of mercury, the orifice between said chambers being proportioned to restrict the entry of mercury vapor but permitting the return of condensed mercury to the main chamber,

and the auxiliary chamber being proportioned to maintain by condensation the pressure of mercury vapor in said main chamber at a value at which the gap between said electrodes will remain of substantially constant length.

4. An electric lamp comprising an en velope providing a main chamber, electrodes of refractory metal mounted therein in close pixtaposition, a quantity of mercury in said container, and means providing a. smaller auxiliary chamber connected to said main chamber by a conduit permitting exchange of vapor and condensed liquid, said auxiliary chamber being of such proportions that the pressure of mercury vapor will be regulated to cause stable operation of said lamp.

5. An electric arc device comprising an elongated container providing a main arc chamber, electrodes of refractory metal at one end of said container in close juxtaposition, a quantity of mercury in said container, a gas at substantial pressure therein, an auxiliary chamber of smaller size than said main chamber connected to said main chamber by a constricted conduit at the end of said container opposite said electrodes, said auxiliary chamber being proportioned to maintain during operation of said device the pressure of vapor in said main container at a value which causes neither disintegration nor accretion of said electrodes.

6. An electric lamp comprising an elongated container, electrodes of tungsten mounted in close 'uxtaposition at one end of said chamber, of an auxiliary container of smaller size than said main container and connected thereto by a throat of suflicient size to permit both the admission of vapor and the return of liquid condensate, a. quan tity of mercury in said main chamber and a filling of gas.

In witness whereof, I have hereunto set my hand this 2d da of October, 1923.

J NATHAN FORGE.

pressure of vapor in said main container at a value which causes neither disintegration nor accretion of said electrodes.

6. An electric lamp comprising an elongated container, electrodes of tungsten mounted in close 'uxtaposition at one end of said chamber, ot an auxiliary container of smaller size than said main container and connected thereto by a throat of suflicient size to permit both the admission of vapor and the return of liquid condensate, a quantity of mercury in said main chamber and a filling of gas.

In witness whereof, I have hereunto set my hand this 2d da of October, 1923.

J NATHAN FORGE.

Certificate of Correction.

It is hereby certified that Letters Patent No. 1,578,973, anted March 30, 1926,

upon the application of Jonathan Force, of Livingston,

ew Jersey, for an improvement in Are Devices, were erroneously issued to the inventor, said Force, whereas said Letters Patent should have been issued to General Electric Company, a oorporatz'an of New York, said corporation being assignee of the entire interest in said invention, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 11th day of May, A. D. 1926.

[emu] M. J. MOORE, Acting Uommiasioner of Patents.

Certificate of Correction.

It is hereby certified that Letters Patent No. 1,578,973, anted March 30, 1926, upon the application of Jonathan Force, of Livingston, ew Jersey, for an improvement in Arc Devices, were erroneously issued to the inventor, said Force, whereas said Letters Patent should have been issued to General Electric Company, a. corporation of New York, said corporation being assignee of the entire interest 1n said invention, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 11th day of May, A. D. 1926.

[emu] M. J. MOORE,

Acting Uomrmbaimr of Patents. 

